Frame structure design for new carrier type (NCT)

ABSTRACT

A system and method utilizes a selected PRB configuration for a new carrier type for a 3GPP-type wireless network. A downlink signal is received that comprises a demodulation reference signal pattern in at least one predetermined subframe of the downlink signal. The subframe comprises a first predetermined number of the plurality of orthogonal frequency division multiplex (OFDM) symbols comprising synchronization signals for a legacy version of the downlink signal and the demodulation reference signal pattern comprising a second predetermined number of OFDM symbols that are different from the first predetermined number of the plurality of OFDM symbols. After receiving the downlink signal, the demodulation reference signal pattern in the downlink signal is demodulated.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present patent application is a continuation of U.S. applicationSer. No. 13/628,129 filed Sep. 27, 2012, pending, which in turn claimsthe benefit of U.S. Provisional Patent Application Ser. No. 61/621,939filed Apr. 9, 2012. Said application Ser. No. 13/628,129 and saidApplication No. 61/621,939 are hereby incorporated by reference hereinin their entireties.

TECHNICAL FIELD

Embodiments described herein are generally directed to the field ofwireless communications.

BACKGROUND

An additional carrier type has been extensively discussed for the RadioLayer 1 (RAN1) of the 3^(rd) Generation Partnership Project (3GPP)collaboration between various telecommunications associations. From theperspective of RAN1, the main motivations for introducing a New CarrierType (NCT) for carrier aggregation include enhanced spectral efficiency,improved support for heterogeneous network, and energy efficiency.

The baseline approach for the Primary Synchronization Signal (PSS) andSecondary Synchronization Signal (SSS) mapping for the NCT is as perRelease 8 (Rel-8) of the 3GPP Mobile Broadband Standard. That is, thePSS/SSS signals for the NCT are mapped onto the last and the next tolast Orthogonal Frequency Division Multiplexing (OFDM) symbols in thecenter six Physical Resource Blocks (PRBs) of the system bandwidth inthe first slot of subframes 0 and 5 according to the 3GPP TS 36.211.While the baseline approach is simplest in terms of specification impactand UE implementation, a Demodulation Reference Signal (DMRS) (alsoreferred to as a User Equipment-Specific Reference Signal forDemodulation (UE-RS)) and PSS/SSS collision issue will occur, asillustrated in FIGS. 1A and 1B. FIG. 1A depicts a Physical ResourceBlock (PRB) for a Frequency-Division Duplexing (FDD) system, and FIG. 1Bdepicts a PRB for a Time-Division Duplexing (TDD) system. A collisionoccurs when the PSS/SSS signals overlap with the DMRS signals, asdepicted by boxed Resource Elements (REs) in the PRBs.

Release 10 (Rel-10) of the 3GPP Standard does not allow UE-RS-basedtransmission schemes in the center six PRBs in subframes 0 and 5 inwhich PSS/SSS signals are transmitted because the UE-RS signal mappingcollides with the legacy PSS/SSS signal mapping at symbols 5 and 6. Inother words, demodulation of Rel-10 uses Cell Specific Reference Signal(CRS) based transmission modes if such collisions occur and the US-RS isnot used. In Release 11 (Rel-11) of the 3GPP Standard, the New CarrierType (NCT) can carry one Reference Signal (RS) port (consisting of theRel-8 CRS Port 0 Resource Elements (REs) per PRB and the Rel-8 sequence)within one subframe with 5 ms periodicity and this RS port (based onRel-8 CRS port) is not used for demodulation.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments disclosed herein are illustrated by way of example, and notby way of limitation, in the figures of the accompanying drawings inwhich like reference numerals refer to similar elements and in which:

FIGS. 1A and 1B respectively depict baseline approaches for a PhysicalResource Block (PRB) for a Frequency-Division Duplexing (FDD) system,and a PRB for a Time-Division Duplexing (TDD) system;

FIG. 2 depicts an exemplary frame structure of a radio frame for a RAN1according to the subject matter disclosed herein;

FIGS. 3A-3I depict different PRB configuration according to the subjectmatter disclosed herein;

FIG. 4 depicts a functional block diagram of an exemplary embodiment ofa wireless station WD 400 according to the subject matter disclosedherein;

FIG. 5 depicts a flow diagram for demodulating a demodulation referencesignal pattern according to the subject matter disclosed herein;

FIG. 6 depicts a block diagram of an exemplary configuration of awireless network in accordance with one or more exemplary embodimentsdisclosed herein;

FIG. 7 shows an exemplary block diagram of the overall architecture of a3GPP LTE network that includes one or more devices that are capable ofutilizing a PRB configuration according to the subject matter disclosedherein;

FIGS. 8 and 9 respectively depict exemplary radio interface protocolstructures between a UE and an eNodeB that are based on a 3GPP-typeradio access network standard and that is capable of utilizing a PRBconfiguration according to the subject matter disclosed herein;

FIG. 10 depicts an exemplary functional block diagram of aninformation-handling system that is capable of utilizing a PRBconfiguration according to the subject matter disclosed herein;

FIG. 11 depicts an isometric view of an exemplary embodiment of theinformation-handling system of FIG. 10 that optionally may include atouch screen in accordance with one or more embodiments disclosedherein; and

FIG. 12 depicts an exemplary embodiment of an article of manufacturecomprising a non-transitory computer-readable storage medium havingstored thereon computer-readable instructions that, when executed by acomputer-type device, results in any of the various techniques andmethods according to the subject matter disclosed herein.

It will be appreciated that for simplicity and/or clarity ofillustration, elements depicted in the figures have not necessarily beendrawn to scale. For example, the dimensions of some of the elements maybe exaggerated relative to other elements for clarity. The scaling ofthe figures does not represent precise dimensions and/or dimensionalratios of the various elements depicted herein. Further, if consideredappropriate, reference numerals have been repeated among the figures toindicate corresponding and/or analogous elements.

DESCRIPTION OF THE EMBODIMENTS

Embodiments of techniques and devices described herein relate towireless communications. In particular, the subject matter disclosedherein relates to configurations of Physical Resource Blocks (PRBs) thatpermit demodulation of Physical Downlink Shared Channel (PDSCH)transmitted in the center six PRBs if the Release 8 (Rel-8) of the 3GPPStandard Primary Synchronization Signal and Secondary SynchronizationSignal (PSS/SSS) mapping (i.e., a legacy PSS/SSS mapping) is used for aNew Carrier Type (NCT). The configurations provided by the subjectmatter disclosed herein avoid collision with Resource Elements (REs) forlegacy UE-Specific RS transmission. In one or more embodiments, the termlegacy may refer to a currently existing or previously existingstandard, including any release, version or implementation thereof,and/or or any device, system, network, or method capable of operating inaccordance therewith, although the scope of the claimed subject matteris not limited in this respect.

In the following description, numerous specific details are set forth toprovide a thorough understanding of embodiments disclosed herein. Oneskilled in the relevant art will recognize, however, that theembodiments disclosed herein can be practiced without one or more of thespecific details, or with other methods, components, materials, and soforth. In other instances, well-known structures, materials, oroperations are not shown or described in detail to avoid obscuringaspects of the specification.

Reference throughout this specification to “one embodiment” or “anembodiment” means that a particular feature, structure or characteristicdescribed in connection with the embodiment is included in at least oneembodiment. Thus, appearances of the phrases “in one embodiment” or “inan embodiment” in various places throughout this specification are notnecessarily all referring to the same embodiment. Furthermore, theparticular features, structures or characteristics may be combined inany suitable manner in one or more embodiments. Additionally, the word“exemplary” is used herein to mean “serving as an example, instance, orillustration.” Any embodiment described herein as “exemplary” is not tobe construed as necessarily preferred or advantageous over otherembodiments.

Various operations may be described as multiple discrete operations inturn and in a manner that is most helpful in understanding the claimedsubject matter. The order of description, however, should not beconstrued as to imply that these operations are necessarily orderdependent. In particular, these operations need not be performed in theorder of presentation. Operations described may be performed in adifferent order than the described embodiment. Various additionaloperations may be performed and/or described operations may be omittedin additional embodiments.

The subject matter disclosed herein relates to configurations ofPhysical Resource Blocks (PRBs) that permit demodulation of PhysicalDownlink Shared Channel (PDSCH) transmitted in the center six PRBs ifthe Release 8 (Rel-8) of the 3GPP Standard Primary SynchronizationSignal and Secondary Synchronization Signal (PSS/SSS) mapping (i.e., alegacy PSS/SSS mapping or legacy synchronization pattern) is used for aNew Carrier Type (NCT). The configurations provided by the subjectmatter disclosed herein avoid collision with Resource Elements (REs) forlegacy UE-Specific RS transmission.

In one exemplary embodiment of the subject matter disclosed herein, aDemodulation Reference Signal (DMRS) (also referred to as a UE-RS)pattern is used in PRBs with collision. Alternatively, the DMRS patternis applied to all PRBs with the same slot or subframe. In anotherexemplary embodiment, the PSS/SSS location in subframes 0 and 5 isselected to avoid collisions. Commonality between TDD and FDD systems isachieved for the DMRS pattern and/or the PSS/SSS locations, and thecollision issue is avoided between UE-RS and PSS/SSS with no degradationon PDSCH performance.

FIG. 2 depicts an exemplary frame structure of a radio frame for a RAN1according to the subject matter disclosed herein. In particular, FIG. 2depicts two types of PRBs occur in subframes 0 and 5, referred to hereinas Type-I PRBs and Type-II PRBs. Type-I PRBs are PRBs with no RS-PSS/SScollisions and Type-II PRBs are PRBs with RS-PSS/SS collisions. TheType-II PRBs are the six central PRBs shown in FIG. 2. According to thesubject matter disclosed herein, for PRBs in subframes 0 and 5 a DMRSpattern is used for UE-specific reference signals for a normal cyclicprefix to avoid a RS-PSS/SSS collision. Such a new DMRS can be used fora slot, or subframe, or can be dependent on the frequency location ofthe PRB (e.g., applied to only the Type-II PRBs). One exemplaryembodiment provides a new DMRS pattern in the central six PRBs ofbandwidth (Type-II PRBs in FIG. 2) and uses a legacy DMRS pattern forother PRBs in the same subframe.

According to the subject matter disclosed herein, UE-RS (i.e., DMRS)patterns are selected to be on non-CRS OFDM symbols to avoid the commonreference signal (CRS) port 0, PSS/SSS signals, PBCH and CSI-RS of alegacy system. Therefore, for a normal Cyclic Prefix (CP) configuration,one exemplary embodiment provides that UE-RS are placed in OFDM symbols2-3 and 12-13 in Type-II PRBs, as shown in FIG. 3A. In another exemplaryembodiment, UE-RS are placed in OFDM symbols 1-2 and 12-13 in Type-IIPRBs, as shown in FIG. 3B.

Channel estimation performance of UE-RS patterns can be significantlyimpacted by the location of the Reference Signal (RS). Generally,placement of the RS on the edges or near the edge OFDM symbols in eachslot provides the best performance for the range of low speeds (3 km/hor 30 km/h) or for the high speeds (120 km/h) over which Rel-10 of the3GPP Mobile Broadband Standard needs to be optimized. FIG. 3C shows oneexemplary embodiment of the subject matter disclosed herein in which theUE-RS patterns are placed in OFDM symbols 0-1 and 12-13 for Type-IIPRBs. The REs for CRS port 0 are punctured by DMRS REs if collisionoccurs, that is, a UE may assume that CRS port 0 are not present in acollision REs, as shown in FIG. 3C.

In another exemplary embodiment of the subject matter disclosed hereinshown in FIG. 3D, the UE-RS patterns are selected for Type-II PRBs to bea “mirror” of a legacy DMRS pattern in each slot considering the legacyPDCCH is not transmitted in NCT. With this mirror configuration, theexemplary embodiment of FIG. 3D provides much better demodulationperformance than the exemplary embodiments of FIGS. 3A-3C forhigher-speeds scenarios while still avoiding collision with legacyPSS/SSS in both FDD and TDD systems. Therefore, the exemplary embodimentof FIG. 3D provides a UE-RS configuration that maximizes DMRS patterncommonality between FDD and TDD systems. Moreover, the exemplaryembodiment of FIG. 3D could also be used at Type-1 PRBs to reduce UEcomplexity by using the same DMRS design for both Type-I and Type-IIPRBs in one subframe, thereby avoiding the need of implementing twoUE-RS channel estimators.

For a TDD-based system, the subject matter disclosed herein provides twoadditional DMRS patterns that are based on principles similar to thosedescribed above. The exemplary embodiment of the subject matterdisclosed herein that is shown in FIG. 3E does not cause extra UEcomplexity by needing an additional UE-RS channel estimator because theconfiguration of this exemplary embodiment corresponds to a legacy DMRSpattern that has been specially designed for the Downlink Pilot TimeSlot (DwPTS) of existing TDD UEs. Accordingly, the exemplary embodimentof FIG. 3E provides a hybrid DMRS pattern for normal subframes 0 and 5.That is, the DRMS pattern of the exemplary embodiment of FIG. 3E is ahybrid because it includes a legacy pattern and a pattern according tothe subject matter disclosed herein. In FIG. 3F, the exemplaryembodiment depicted shifts a legacy DMRS pattern by one OFDM symbol toavoid the collision with SSS sequence in TDD system.

FIGS. 3G-3I respectively depict additional exemplary embodiments of thesubject matter disclosed herein. In FIGS. 3G and 3H, the PSS/SSS symbolsare respectively remapped on the first or second two consecutive OFDMsymbols within a subframe. In FIG. 3I, the PSS/SSS symbols are remappedinto the second and fourth OFDM symbols within a subframe. These threeexemplary embodiments provide coherent detection of the SSS using thePSS, thereby providing better detection performance over anon-consecutive OFDM-symbol configuration. Additionally, the exemplaryconfigurations of FIGS. 3G-3I avoid collisions with legacy DMRS, PBCHand CSI-RS, while achieving PSS/SSS commonality between TDD and FDDsystem.

FIG. 4 depicts a functional block diagram of an exemplary embodiment ofa wireless station WD 400 according to the subject matter disclosedherein. Wireless device 400 comprises at least one antenna 401 and areceiver 402 coupled in a well-known manner to antenna 401. In oneexemplary embodiment, wireless device 400 also comprises a processor 403and a transmitter 404.

Antenna 401 receives a downlink signal from a wireless network, such asa 3GPP-based network utilizing a New Carrier Type (NCT). The downlinksignal comprises a demodulation reference signal pattern in at least onepredetermined subframe of the downlink signal, such as depicted in FIG.2. The at least one subframe comprises a first predetermined number ofthe plurality of orthogonal frequency division multiplex (OFDM) symbolscomprising synchronization signals for a legacy version of the downlinksignal, such as the 3GPP PSS/SSS mapped into the New Carrier Type (NCT).According to the subject matter disclosed herein, the demodulationreference signal pattern comprises a second predetermined number of OFDMsymbols that are different from the first predetermined number of theplurality of OFDM symbols. Receiver 402 demodulates the demodulationreference signal pattern in the downlink signal in a well-known manner.

In one exemplary embodiment, wireless device 400 comprises, but is notlimited to, a cellular telephone, smartphone, smart-type device, ortablet-type device. In another exemplary embodiment, wireless devicecomprising a touchscreen display capable of receiving input informationfrom a touch of a user or a stylus, such as disclosed herein inconnection with FIGS. 10 and 11.

FIG. 5 depicts a flow diagram 500 for demodulating a demodulationreference signal pattern according to the subject matter disclosedherein. At 501, a downlink signal is received, such that the downlinksignal comprises a demodulation reference signal pattern in at least onepredetermined subframe of the downlink signal. At least one subframe ofthe downlink signal comprises a first predetermined number of theplurality of orthogonal frequency division multiplex (OFDM) symbolscomprising synchronization signals for a legacy version of the downlinksignal. The demodulation reference signal pattern comprises a secondpredetermined number of OFDM symbols that are different from the firstpredetermined number of the plurality of OFDM symbols. At 502, thedemodulation reference signal pattern in the downlink signal isdemodulated in a well-known manner.

In one exemplary embodiment, the at least one subframe of the downlinksignal comprises a plurality of physical resource blocks (PRBs), suchthat each PRB comprises a selected portion of a frequency bandwidth ofthe at least one subframe and comprising a predetermined number of OFDMsymbols. For this exemplary embodiment, the demodulation referencesignal pattern of a PRB is based on a bandwidth position of a PRB in theat least one subframe, such as described in connection with Type-I andType-II PRBs.

In another exemplary embodiment, at least one PRB of the at least onesubframe comprises OFDM symbols respectively identified as OFDM symbols0-13, and the demodulation reference signal pattern comprises OFDMsymbols 0-1 and 7-8 of the PRB, such as depicted in FIG. 3D.

In another exemplary embodiment, the demodulation reference signalpattern comprises a first OFDM symbol pattern for a first plurality ofphysical resource blocks of the at least one subframe and a second OFDMsymbol pattern for a second plurality of physical resource blocks of theat least one subframe, such that the second plurality of physicalresource blocks comprises a predetermined number of physical resourceblocks adjacent to a center frequency of the at least one subframe. Inyet another exemplary embodiment, the demodulation reference signalpattern comprises OFDM symbols 2-3 and 12-13 of the PRB, such asdepicted in FIG. 3A. In another exemplary embodiment, the demodulationreference signal pattern comprises OFDM symbols 1-2 and 12-13 of thePRB, such as depicted in FIG. 3B. In still another exemplary embodiment,the demodulation reference signal pattern comprises OFDM symbols 0-1 and12-13 of the PRB, such as depicted in FIG. 3C. In other exemplaryembodiments, the demodulation reference signal pattern comprises OFDMsymbols 5-6 and 9-10 of the PRB (FIG. 3E), OFDM symbols 5-6 and 12-13 ofthe PRB (FIG. 3F). Still other exemplary embodiments are depicted inFIGS. 3G-3I.

FIG. 6 depicts a block diagram of an exemplary configuration of awireless network 600 in accordance with one or more exemplaryembodiments disclosed herein. One or more of the elements of wirelessnetwork 600 may be capable of utilizing a PRB configuration according tothe subject matter disclosed herein. As shown in FIG. 6, network 600 maybe an Internet-Protocol-type (IP-type) network comprising anInternet-type network 610, or the like, that is capable of supportingmobile wireless access and/or fixed wireless access to Internet 610. Inone or more exemplary embodiments, network 600 may be in compliance witha Worldwide Interoperability for Microwave Access (WiMAX) standard orfuture generations of WiMAX, and in one particular embodiment may be incompliance with an Institute for Electrical and Electronics Engineers802.16-based standard (for example, IEEE 802.16e), or an IEEE802.11-based standard (for example, IEEE 802.11 a/b/g/n standard), andso on. In one or more alternative exemplary embodiments, network 600 maybe in compliance with a Third Generation Partnership Project Long TermEvolution (3GPP LTE), a 3GPP2 Air Interface Evolution (3GPP2 AIE)standard and/or a 3GPP LTE-Advanced standard. In general, network 600may comprise any type oforthogonal-frequency-division-multiple-access-based (OFDMA-based)wireless network, for example, a WiMAX compliant network, a Wi-FiAlliance Compliant Network, a digital subscriber-line-type (DSL-type)network, an asymmetric-digital-subscriber-line-type (ADSL-type) network,an Ultra-Wideband (UWB) compliant network, a Wireless Universal SerialBus (USB) compliant network, a 4th Generation (4G) type network, and soon, and the scope of the claimed subject matter is not limited in theserespects. As an example of mobile wireless access, access servicenetwork (ASN) 612 is capable of coupling with base station (BS) 614 toprovide wireless communication between subscriber station (SS) 616 (alsoreferred to herein as a wireless terminal) and Internet 610. In oneexemplary embodiment, subscriber station 616 may comprise a mobile-typedevice or information-handling system capable of wirelesslycommunicating via network 600, for example, a notebook-type computer, acellular telephone, a personal digital assistant, an M2M-type device, orthe like. In another exemplary embodiment, subscriber station is capableof utilizing a PRB configuration according to the subject matterdisclosed herein. ASN 612 may implement profiles that are capable ofdefining the mapping of network functions to one or more physicalentities on network 600. Base station 614 may comprise radio equipmentto provide radio-frequency (RF) communication with subscriber station616, and may comprise, for example, the physical layer (PHY) and mediaaccess control (MAC) layer equipment in compliance with an IEEE802.16e-type standard. Base station 614 may further comprise an IPbackplane to couple to Internet 610 via ASN 612, although the scope ofthe claimed subject matter is not limited in these respects.

Network 600 may further comprise a visited connectivity service network(CSN) 624 capable of providing one or more network functions including,but not limited to, proxy and/or relay type functions, for example,authentication, authorization and accounting (AAA) functions, dynamichost configuration protocol (DHCP) functions, or domain-name servicecontrols or the like, domain gateways, such as public switched telephonenetwork (PSTN) gateways or Voice over Internet Protocol (VoIP) gateways,and/or Internet-Protocol-type (IP-type) server functions, or the like.These are, however, merely example of the types of functions that arecapable of being provided by visited CSN or home CSN 626, and the scopeof the claimed subject matter is not limited in these respects. VisitedCSN 624 may be referred to as a visited CSN in the case, for example, inwhich visited CSN 624 is not part of the regular service provider ofsubscriber station 616, for example, in which subscriber station 616 isroaming away from its home CSN, such as home CSN 626, or, for example,in which network 600 is part of the regular service provider ofsubscriber station, but in which network 600 may be in another locationor state that is not the main or home location of subscriber station616. In a fixed wireless arrangement, WiMAX-type customer premisesequipment (CPE) 622 may be located in a home or business to provide homeor business customer broadband access to Internet 610 via base station620, ASN 618, and home CSN 626 in a manner similar to access bysubscriber station 616 via base station 614, ASN 612, and visited CSN624, a difference being that WiMAX CPE 622 is generally disposed in astationary location, although it may be moved to different locations asneeded, whereas subscriber station may be utilized at one or morelocations if subscriber station 616 is within range of base station 614for example. It should be noted that CPE 622 need not necessarilycomprise a WiMAX-type terminal, and may comprise other types ofterminals or devices compliant with one or more standards or protocols,for example, as discussed herein, and in general may comprise a fixed ora mobile device. Moreover, in one exemplary embodiment, CPE 622 iscapable of utilizing a PRB configuration according to the subject matterdisclosed herein. In accordance with one or more embodiments, operationsupport system (OSS) 628 may be part of network 600 to providemanagement functions for network 600 and to provide interfaces betweenfunctional entities of network 600. Network 600 of FIG. 6 is merely onetype of wireless network showing a certain number of the components ofnetwork 600; however, the scope of the claimed subject matter is notlimited in these respects.

FIG. 7 shows an exemplary block diagram of the overall architecture of a3GPP LTE network 700 that includes one or more devices that are capableof utilizing a PRB configuration according to the subject matterdisclosed herein. FIG. 7 also generally shows exemplary network elementsand exemplary standardized interfaces. At a high level, network 700comprises a core network (CN) 701 (also referred to as an evolved PacketSystem (EPC)), and an air-interface access network E-UTRAN 702. CN 701is responsible for the overall control of the various User Equipment(UE) connected to the network and establishment of the bearers. CN 701may include functional entities, such as a home agent HA and/or an ANDSFserver or entity, although not explicitly depicted. E-UTRAN 702 isresponsible for all radio-related functions.

The main exemplary logical nodes of CN 701 include, but are not limitedto, a Serving GPRS Support Node 703, the Mobility Management Entity 704,a Home Subscriber Server (HSS) 705, a Serving Gate (SGW) 706, a PDNGateway 707 and a Policy and Charging Rules Function (PCRF) Manager 708.The functionality of each of the network elements of CN 701 is wellknown and is not described herein. Each of the network elements of CN701 are interconnected by well-known exemplary standardized interfaces,some of which are indicated in FIG. 7, such as interfaces S3, S4, S5,etc., although not described herein.

While CN 701 includes many logical nodes, the E-UTRAN access network 702is formed by at least one node, such as evolved NodeB (base station(BS), eNB or eNodeB) 710, which connects to one or more User Equipment(UE) 711, of which only one is depicted in FIG. 7. UE 711 is alsoreferred to herein as a wireless device (WD) and/or a subscriber station(SS), and can include an M2M-type device. In one exemplary embodiment,UE 711 is capable of utilizing a PRB configuration according to thesubject matter disclosed herein. In one exemplary configuration, asingle cell of an E-UTRAN access network 702 provides one substantiallylocalized geographical transmission point (having multiple antennadevices) that provides access to one or more UEs. In another exemplaryconfiguration, a single cell of an E-UTRAN access network 702 providesmultiple geographically substantially isolated transmission points (eachhaving one or more antenna devices) with each transmission pointproviding access to one or more UEs simultaneously and with thesignaling bits defined for the one cell so that all UEs share the samespatial signaling dimensioning. For normal user traffic (as opposed tobroadcast), there is no centralized controller in E-UTRAN; hence theE-UTRAN architecture is said to be flat. The eNBs are normallyinterconnected with each other by an interface known as “X2” and to theEPC by an S1 interface. More specifically, an eNB is connected to MME704 by an S1-MME interface and to SGW 706 by an S1-U interface. Theprotocols that run between the eNBs and the UEs are generally referredto as the “AS protocols.” Details of the various interfaces are wellknown and not described herein.

The eNB 710 hosts the PHYsical (PHY), Medium Access Control (MAC), RadioLink Control (RLC), and Packet Data Control Protocol (PDCP) layers,which are not shown in FIG. 7, and which include the functionality ofuser-plane header-compression and encryption. The eNB 710 also providesRadio Resource Control (RRC) functionality corresponding to the controlplane, and performs many functions including radio resource management,admission control, scheduling, enforcement of negotiated Up Link (UL)QoS, cell information broadcast, ciphering/deciphering of user andcontrol plane data, and compression/decompression of DL/UL user planepacket headers.

The RRC layer in eNB 710 covers all functions related to the radiobearers, such as radio bearer control, radio admission control, radiomobility control, scheduling and dynamic allocation of resources to UEsin both uplink and downlink, header compression for efficient use of theradio interface, security of all data sent over the radio interface, andconnectivity to the EPC. The RRC layer makes handover decisions based onneighbor cell measurements sent by UE 711, generates pages for UEs 711over the air, broadcasts system information, controls UE measurementreporting, such as the periodicity of Channel Quality Information (CQI)reports, and allocates cell-level temporary identifiers to active UEs711. The RRC layer also executes transfer of UE context from a sourceeNB to a target eNB during handover, and provides integrity protectionfor RRC messages. Additionally, the RRC layer is responsible for thesetting up and maintenance of radio bearers.

FIGS. 8 and 9 respectively depict exemplary radio interface protocolstructures between a UE and an eNodeB that are based on a 3GPP-typeradio access network standard and that is capable of utilizing a PRBconfiguration according to the subject matter disclosed herein. Morespecifically, FIG. 8 depicts individual layers of a radio protocolcontrol plane and FIG. 9 depicts individual layers of a radio protocoluser plane. The protocol layers of FIGS. 6 and 7 can be classified intoan L1 layer (first layer), an L2 layer (second layer) and an L3 layer(third layer) on the basis of the lower three layers of the OSIreference model widely known in communication systems.

The physical (PHY) layer, which is the first layer (L1), provides aninformation transfer service to an upper layer using a physical channel.The physical layer is connected to a Medium Access Control (MAC) layer,which is located above the physical layer, through a transport channel.Data is transferred between the MAC layer and the PHY layer through thetransport channel. A transport channel is classified into a dedicatedtransport channel and a common transport channel according to whether ornot the channel is shared. Data transfer between different physicallayers, specifically between the respective physical layers of atransmitter and a receiver is performed through the physical channel.

A variety of layers exist in the second layer (L2 layer). For example,the MAC layer maps various logical channels to various transportchannels, and performs logical-channel multiplexing for mapping variouslogical channels to one transport channel. The MAC layer is connected tothe Radio Link Control (RLC) layer serving as an upper layer through alogical channel. The logical channel can be classified into a controlchannel for transmitting information of a control plane and a trafficchannel for transmitting information of a user plane according tocategories of transmission information.

The RLC layer of the second layer (L2) performs segmentation andconcatenation on data received from an upper layer, and adjusts the sizeof data to be suitable for a lower layer transmitting data to a radiointerval. In order to guarantee various Qualities of Service (QoSs)requested by respective radio bearers (RBs), three operation modes,i.e., a Transparent Mode (TM), an Unacknowledged Mode (UM), and anAcknowledged Mode (AM), are provided. Specifically, an AM RLC performs aretransmission function using an Automatic Repeat and Request (ARQ)function so as to implement reliable data transmission.

A Packet Data Convergence Protocol (PDCP) layer of the second layer (L2)performs a header compression function to reduce the size of an IPpacket header having relatively large and unnecessary controlinformation in order to efficiently transmit IP packets, such as IPv4 orIPv6 packets, in a radio interval with a narrow bandwidth. As a result,only information required for a header part of data can be transmitted,so that transmission efficiency of the radio interval can be increased.In addition, in an LTE-based system, the PDCP layer performs a securityfunction that includes a ciphering function for preventing a third partyfrom eavesdropping on data and an integrity protection function forpreventing a third party from handling data.

A Radio Resource Control (RRC) layer located at the top of the thirdlayer (L3) is defined only in the control plane and is responsible forcontrol of logical, transport, and physical channels in association withconfiguration, re-configuration and release of Radio Bearers (RBs). TheRB is a logical path that the first and second layers (L1 and L2)provide for data communication between the UE and the UTRAN. Generally,Radio Bearer (RB) configuration means that a radio protocol layer neededfor providing a specific service, and channel characteristics aredefined and their detailed parameters and operation methods areconfigured. The Radio Bearer (RB) is classified into a Signaling RB(SRB) and a Data RB (DRB). The SRB is used as a transmission passage ofRRC messages in the C-plane, and the DRB is used as a transmissionpassage of user data in the U-plane.

A downlink transport channel for transmitting data from the network tothe UE may be classified into a Broadcast Channel (BCH) for transmittingsystem information and a downlink Shared Channel (SCH) for transmittinguser traffic or control messages. Traffic or control messages of adownlink multicast or broadcast service may be transmitted through adownlink SCH and may also be transmitted through a downlink multicastchannel (MCH). Uplink transport channels for transmission of data fromthe UE to the network include a Random Access Channel (RACH) fortransmission of initial control messages and an uplink SCH fortransmission of user traffic or control messages.

Downlink physical channels for transmitting information transferred to adownlink transport channel to a radio interval between the UE and thenetwork are classified into a Physical Broadcast Channel (PBCH) fortransmitting BCH information, a Physical Multicast Channel (PMCH) fortransmitting MCH information, a Physical Downlink Shared Channel (PDSCH)for transmitting downlink SCH information, and a Physical DownlinkControl Channel (PDCCH) (also called a DL L1/L2 control channel) fortransmitting control information, such as DL/UL Scheduling Grantinformation, received from first and second layers (L1 and L2). In themeantime, uplink physical channels for transmitting informationtransferred to an uplink transport channel to a radio interval betweenthe UE and the network are classified into a Physical Uplink SharedChannel (PUSCH) for transmitting uplink SCH information, a PhysicalRandom Access Channel for transmitting RACH information, and a PhysicalUplink Control Channel (PUCCH) for transmitting control information,such as Hybrid Automatic Repeat Request (HARQ) ACK or NACK SchedulingRequest (SR) and Channel Quality Indicator (CQI) report information,received from first and second layers (L1 and L2).

FIG. 10 depicts an exemplary functional block diagram of aninformation-handling system 1000 that is capable of utilizing a PRBconfiguration according to the subject matter disclosed herein.Information-handling system 1000 of FIG. 10 may tangibly embody one ormore of any of the exemplary devices, exemplary network elements and/orfunctional entities of the network as shown in and described withrespect to FIG. 4, FIG. 6, and/or core network 701 as shown in anddescribed with respect to FIG. 7. In one exemplary embodiment,information-handling system 1000 may represent the components ofwireless device 400, subscriber station 616, CPE 622, base stations 614and 620, eNB 710, and/or UE 711, with greater or fewer componentsdepending on the hardware specifications of the particular device ornetwork element. In another exemplary embodiment, information-handlingsystem may provide M2M-type device capability. In yet another exemplaryembodiment, information-handling system 1000 is capable of utilizing aPRB configuration according to the subject matter disclosed herein.Although information-handling system 1000 represents one example ofseveral types of computing platforms, information-handling system 1000may include more or fewer elements and/or different arrangements ofelements than shown in FIG. 10, and the scope of the claimed subjectmatter is not limited in these respects.

In one or more embodiments, information-handling system 1000 maycomprise one or more applications processor 1010 and a basebandprocessor 1012. Applications processor 1010 may be utilized as a generalpurpose processor to run applications and the various subsystems forinformation-handling system 1000, and to capable of utilizing a PRBconfiguration according to the subject matter disclosed herein.Applications processor 1010 may include a single core or alternativelymay include multiple processing cores wherein one or more of the coresmay comprise a digital signal processor or digital signal processingcore. Furthermore, applications processor 1010 may include a graphicsprocessor or coprocessor disposed on the same chip, or alternatively agraphics processor coupled to applications processor 1010 may comprise aseparate, discrete graphics chip. Applications processor 1010 mayinclude on-board memory, such as cache memory, and further may becoupled to external memory devices such as synchronous dynamic randomaccess memory (SDRAM) 1014 for storing and/or executing applications,such as capable of utilizing a PRB configuration according to thesubject matter disclosed herein. During operation, and NAND flash 1016for storing applications and/or data even when information-handlingsystem 1000 is powered off.

In one exemplary embodiment, a list of candidate nodes may be stored inSDRAM 1014 and/or NAND flash 1016. Further, applications processor 1010may execute computer-readable instructions stored in SDRAM 1014 and/orNAND flash 1016 that result in utilizing a PRB configuration accordingto the subject matter disclosed herein.

In one exemplary embodiment, baseband processor 1012 may control thebroadband radio functions for information-handling system 1000. Basebandprocessor 1012 may store code for controlling such broadband radiofunctions in a NOR flash 1018. Baseband processor 1012 controls awireless wide area network (WWAN) transceiver 1020 which is used formodulating and/or demodulating broadband network signals, for example,for communicating via a 3GPP LTE network or the like as discussed hereinwith respect to FIG. 10. The WWAN transceiver 1020 couples to one ormore power amplifiers 1022 that are respectively coupled to one or moreantennas 1024 for sending and receiving radio-frequency signals via theWWAN broadband network. The baseband processor 1012 also may control awireless local area network (WLAN) transceiver 1026 coupled to one ormore suitable antennas 1028 and that may be capable of communicating viaa Bluetooth-based standard, an IEEE 802.11-based standard, an IEEE802.16-based standard, an IEEE 802.18-based wireless network standard, a3GPP-based protocol wireless network, a Third Generation PartnershipProject Long Term Evolution (3GPP LTE) based wireless network standard,a 3GPP2 Air Interface Evolution (3GPP2 AIE) based wireless networkstandard, a 3GPP-LTE-Advanced-based wireless network, a UMTS-basedprotocol wireless network, a CDMA2000-based protocol wireless network, aGSM-based protocol to wireless network, acellular-digital-packet-data-based (CDPD-based) protocol wirelessnetwork, a Mobitex-based protocol wireless network, aNear-Field-Communications-based (NFC-based) link, a WiGig-based network,a ZigBee-based network, or the like. It should be noted that these aremerely exemplary implementations for applications processor 1010 andbaseband processor 1012, and the scope of the claimed subject matter isnot limited in these respects. For example, any one or more of SDRAM1014, NAND flash 1016 and/or NOR flash 1018 may comprise other types ofmemory technology, such as magnetic-based memory, chalcogenide-basedmemory, phase-change-based memory, optical-based memory, or ovonic-basedmemory, and the scope of the claimed subject matter is not limited inthis respect.

In one or more embodiments, applications processor 1010 may drive adisplay 1030 for displaying various information or data, and may furtherreceive touch input from a user via a touch screen 1032, for example,via a finger or a stylus. In one exemplary embodiment, screen 1032display a menu and/or options to a user that are selectable via a fingerand/or a stylus for entering information into information-handlingsystem 1000.

An ambient light sensor 1034 may be utilized to detect an amount ofambient light in which information-handling system 1000 is operating,for example, to control a brightness or contrast value for display 1030as a function of the intensity of ambient light detected by ambientlight sensor 1034. One or more cameras 1036 may be utilized to captureimages that are processed by applications processor 1010 and/or at leasttemporarily stored in NAND flash 1016. Furthermore, applicationsprocessor may be coupled to a gyroscope 1038, accelerometer 1040,magnetometer 1042, audio coder/decoder (CODEC) 1044, and/or globalpositioning system (GPS) controller 1046 coupled to an appropriate GPSantenna 1048, for detection of various environmental propertiesincluding location, movement, and/or orientation of information-handlingsystem 1000. Alternatively, controller 1046 may comprise a GlobalNavigation Satellite System (GNSS) controller. Audio CODEC 1044 may becoupled to one or more audio ports 1050 to provide microphone input andspeaker outputs either via internal devices and/or via external devicescoupled to information-handling system via the audio ports 1050, forexample, via a headphone and microphone jack. In addition, applicationsprocessor 1010 may couple to one or more input/output (I/O) transceivers1052 to couple to one or more I/O ports 1054 such as a universal serialbus (USB) port, a high-definition multimedia interface (HDMI) port, aserial port, and so on. Furthermore, one or more of the I/O transceivers1052 may couple to one or more memory slots 1056 for optional removablememory, such as secure digital (SD) card or a subscriber identity module(SIM) card, although the scope of the claimed subject matter is notlimited in these respects.

FIG. 11 depicts an isometric view of an exemplary embodiment of theinformation-handling system of FIG. 10 that optionally may include atouch screen in accordance with one or more embodiments disclosedherein. FIG. 11 shows an example implementation of information-handlingsystem 1000 of FIG. 10 tangibly embodied as a cellular telephone,smartphone, smart-type device, or tablet-type device or the like, thatis capable of utilizing a PRB configuration according to the subjectmatter disclosed herein. In one or more embodiments, theinformation-handling system 1000 may comprise any one of theinfrastructure nodes, wireless device 400, subscriber station 616, CPE622, mobile station UE 711 of FIG. 7, and/or an M2M-type device,although the scope of the claimed subject matter is not limited in thisrespect. The information-handling system 1000 may comprise a housing1110 having a display 1030 that may include a touch screen 1032 forreceiving tactile input control and commands via a finger 1116 of a userand/or a via stylus 1118 to control one or more applications processors1010. The housing 1110 may house one or more components ofinformation-handling system 800, for example, one or more applicationsprocessors 1010, one or more of SDRAM 1014, NAND flash 1016, NOR flash1018, baseband processor 1012, and/or WWAN transceiver 1020. Theinformation-handling system 1000 further may optionally include aphysical actuator area 1120 which may comprise a keyboard or buttons forcontrolling information-handling system via one or more buttons orswitches. The information-handling system 1000 may also include a memoryport or slot 1056 for receiving non-volatile memory, such as flashmemory, for example, in the form of a secure digital (SD) card or asubscriber identity module (SIM) card. Optionally, theinformation-handling system 1000 may further include one or morespeakers and/or microphones 1124 and a connection port 1054 forconnecting the information-handling system 1000 to another electronicdevice, dock, display, battery charger, and so on. Additionally,information-handling system 1000 may include a headphone or speaker jack1128 and one or more cameras 836 on one or more sides of the housing1110. It should be noted that the information-handling system 1000 ofFIGS. 10 and 11 may include more or fewer elements than shown, invarious arrangements, and the scope of the claimed subject matter is notlimited in this respect.

FIG. 12 depicts an exemplary embodiment of an article of manufacture1200 comprising a non-transitory computer-readable storage medium 1201having stored thereon computer-readable instructions that, when executedby a computer-type device, results in any of the various techniques andmethods according to the subject matter disclosed herein. Exemplarycomputer-readable storage mediums that could be used forcomputer-readable storage medium 1201 could be, but are not limited to,a semiconductor-based memory, an optically based memory, amagnetic-based memory, or a combination thereof.

These modifications can be made in light of the above detaileddescription. The terms used in the following claims should not beconstrued to limit the scope to the specific embodiments disclosed inthe specification and the claims. Rather, the scope of the embodimentsdisclosed herein is to be determined by the following claims, which areto be construed in accordance with established doctrines of claiminterpretation.

The invention claimed is:
 1. An apparatus comprising processing circuitry to: receive a downlink signal from a transmitter, the downlink signal comprising a radio frame having multiple subframes comprising a band of physical resource blocks (PRBs), the PRBs comprising orthogonal frequency division multiplex (OFDM) symbols; demodulate the received downlink signal using a first demodulation reference signal (DMRS) pattern for a first group of PRBs having a potential for collisions with one or more synchronization signals, wherein the first group of PRBs comprises a center group of six PRBs disposed about a center of system bandwidth; and demodulate the received downlink signal using a second DMRS pattern for a second group of PRBs without a potential for collisions with one or more synchronization signals, wherein the second group of PRBs comprises a group of PRBs located outside the center group of six PRBs; wherein the first DMRS pattern is arranged to avoid collision between a reference signal and a synchronization signal; and wherein the first DMRS pattern for the first group of PRBs comprises UE reference signals on OFDM symbols 0-1 and 7-8 for one or more PRBs of the first group of PRBs, and wherein the first DMRS pattern is used as the second DMRS pattern for the second group of PRBs in one or more subframes.
 2. An apparatus as claimed in claim 1, wherein first DMRS pattern and the second DMRS pattern are applied in PRBs of subframe 0 and subframe 5 of the radio frame.
 3. An apparatus as claimed in claim 1, wherein the first group of PRBs are centered about the center of the band, and the second group of PRBs are disposed at a lower end and an upper and of the band.
 4. An apparatus as claimed in claim 1, wherein the first DMRS pattern comprises UE reference signals on OFDM symbols 2-3 and 12-13 for one or more PRBs of the first group of PRBs.
 5. An apparatus as claimed in claim 1, wherein the first DMRS pattern comprises UE reference signals on OFDM symbols 1-2 and 12-13 for one or more PRBs of the first group of PRBs.
 6. An apparatus as claimed in claim 1, wherein the first DMRS pattern comprises UE reference signals on OFDM symbols 0-1 and 12-13 for one or more PRBs of the first group of PRBs, wherein resource elements for cell specific reference signal (CRS) port 0 are not present for any collision resource elements.
 7. An apparatus as claimed in claim 1, wherein the first DMRS pattern comprises UE reference signals on OFDM symbols 5-6 in an even slot, and OFDM symbols 2-3 in an odd slot, for one or more PRBs of the first group of PRBs.
 8. An apparatus as claimed in claim 1, wherein the first DMRS pattern comprises UE reference signals on OFDM symbols 5-6 in an even slot, and OFDM symbols 4-5 in an odd slot, for one or more PRBs of the first group of PRBs.
 9. An apparatus as claimed in claim 1, wherein the processing circuitry is disposed in a user equipment (UE).
 10. An apparatus as claimed in claim 1, further comprising a touch screen to control an input of the apparatus.
 11. An article of manufacture comprising a non-transitory medium having stored thereon instructions that, if executed, result in: receiving a downlink signal from a transmitter, the downlink signal comprising a radio frame having multiple subframes comprising a band of physical resource blocks (PRBs), the PRBs comprising orthogonal frequency division multiplex (OFDM) symbols; demodulating the received downlink signal using a first demodulation reference signal (DMRS) pattern for a first group of PRBs having a potential for collisions with one or more synchronization signals, wherein the first group of PRBs comprises a center group of six PRBs disposed about a center of system bandwidth; and demodulating the received downlink signal using a second DMRS pattern for a second group of PRBs without a potential for collisions with one or more synchronization signals wherein the second group of PRBs comprises a group of PRBs located outside the center group of six PRBs; wherein the first DMRS pattern is arranged to avoid collision between a reference signal of the transceiver and a synchronization signal; and wherein the first DMRS pattern for the first group of PRBs comprises UE reference signals on OFDM symbols 0-1 and 7-8 for one or more PRBs of the first group of PRBs, and wherein the first DMRS pattern is used as the second DMRS pattern for the second group of PRBs in one or more subframes.
 12. An article of manufacture as claimed in claim 11, wherein first DMRS pattern and the second DMRS pattern are applied in PRBs of subframe 0 and subframe 5 of the radio frame.
 13. An article of manufacture as claimed in claim 11, wherein the first group of PRBs are centered about the center of the band, and the second group of PRBs are disposed at a lower end and an upper and of the band.
 14. An article of manufacture as claimed in claim 11, wherein the first DMRS pattern comprises UE reference signals on OFDM symbols 2-3 and 12-13 for one or more PRRBs of the first group of PRBs.
 15. An article of manufacture as claimed in claim 11, wherein the first DMRS pattern comprises UE reference signals on OFDM symbols 1-2 and 12-13 for one or more PRBs of the first group of PRBs.
 16. An article of manufacture as claimed in claim 11, wherein the first DMRS pattern comprises UE reference signals on OFDM symbols 0-1 and 12-13 for one or more PRBs of the first group of PRBs, wherein resource elements for cell specific reference signal (CRS) port 0 are not present for any collision resource elements.
 17. An article of manufacture as claimed in claim 11, wherein the first DMRS pattern comprises UE reference signals on OFDM symbols 5-6 in an even slot, and OFDM symbols 2-3 in an odd slot, for one or more PRBs of the first group of PRBs.
 18. An article of manufacture as claimed in claim 11, wherein the first DMRS pattern comprises UE reference signals on OFDM symbols 5-6 in an even slot, and OFDM symbols 4-5 in an odd slot, for one or more PRBs of the first group of PRBs. 